验证KeyPress事件处理程序中的字符

Question

I have a form with MaskedTextBoxField where I would like to enable adding only hexadecimal values. Length of the hexadecimal value is fixed to 16 characters, first six digits are always the same, and there is a dash after every two characters.

I have set Mask property on this field to "\\0\\0-15-4F-AA-AA-AA-AA-AA" to allow only alphanumerics. But this way, I am able to enter all letters, not only "af" and "AF".

In KeyPress event is following code:

char c = e.KeyChar;
if (('G' <= c && c <= 'Z') || ('g' <= c && c <= 'z'))
{
  e.Handled = true;
}

When I run this code, application gets to this part, but even then, characters 'GZ' and 'gz' are still entered in MaskedTextBox. How can I prevent this characters being accepted in this MaskedTextBox?

Answer 1

use keycode insted of keychar so you can essaly handle this code
e.keycode;